The goal of this project is to utilize brain mapping methods, both fMRI and ERPs, as well as computational modeling, to examine the neural mechanisms involved in cognitive control, which include processes requiring the selection, manipulation, inhibition, and evaluation of information. There are two main aims. The first main aim is to test the validity of our neural model of cognitive control using fMRI, ERPs, and computational modeling as a way to elucidate the organization of prefrontal cortex for executive function. We will test the hypothesis that control occurs via a cascade of processing involving distinct regions of prefrontal cortex, each of which is involved in selection of a distinct type of mental representation. We will do so via empirical studies in which fMRI and ERP data are collected in parallel and via computational model that is structured to represent the interdependences between prefrontal brain regions that play a role in the cascade. The second main aim is to to investigate the hypothesis that the neural substrates involved in the inhibition or suppression of internal mental representations are distinct from those involved in amplification or maintenance of internal mental representations. These studies will use fMRI to investigate the neural substrates involved in the selection, amplification, and suppression of thoughts using two novel paradigms. This project addresses both of the major questions that the center is examining, namely the nature of the organization of prefrontal cortex for executive function and the cognitive underpinnings of executive function. The work to be performed in in this project is designed to interface with parallel investigations regarding the organizaiton of prefrontal cortex in Projects 2 3, and 5, and parallel investigations about the cognitive components of executive function in Projects 2,3, 4 and 5. Of note, as with all other projects in the center, it examines these quesitons at the neurobiological, psychological and computational levels of analysis. Results from this project will expand our understanding of how cognitive control processes can be implemented by the brain. Such findings have large-ranging implications for psychiatric disorders involving: (i) attentional dysfunction, such as attention-deficit hyperactivity disorder,(ii) ruminative thought patterns, such as obsessive-compulsive disorder, (iii) the intrusion of unwanted thoughts and images, such as posttraumatic stress disorder, and (iv) disorders in which the attribution of thoughts as self-generated as compared to emanating from others is blurred, such as schizophrenia.